IOWA CITY, Iowa _ Fifty years ago, Don Nelson left the University of Iowa eight credits and a student-teaching requirement shy of a degree. Nelson took correspondence classes to complete the credits. But it took the most coaching wins in NBA history for the university to decide Nelson didn’t need to be a student teacher to earn a diploma.

On Saturday, the former Hawkeyes’ star player returned to receive his bachelor’s degree in physical education during Iowa’s commencement ceremony at Carver-Hawkeye Arena.

“I’ve been waiting for this moment for a long, long time. I wish it would have happened 50 years ago. But it didn’t,” Nelson said, “and I think that the morale to that story is it’s never too late as long as you keep working and keep having dreams. They can come true.”

Nelson is known for the 1,355 coaching wins he picked up over 31 seasons as an NBA coach, a career he wrapped up with Golden State following the 2010-11 season. It’s easy to forget that it all started over five decades ago in the Midwest.

Nelson, who turns 72 on May 15, starred for Rock Island High in Illinois, just across the river from Iowa, and joined the Hawkeyes in 1959. Sporting a spiky blond flat top and a versatile game that would serve him well in the pros, Nelson finished his Iowa career as a two-time All-American.

But he left Iowa City just before he finished school. Nelson was picked by Chicago in third round of the NBA Draft and embarked on a memorable 14-year career. He spent the last 11 seasons with the Boston Celtics, winning NBA titles while gaining a reputation as one of the best bench players in history.

The Celtics retired his No. 19 jersey in 1978. Iowa has yet to retire his No. 15, though Nelson said Saturday such an honor from the school isn’t important to him. Nelson went into coaching and quickly became known for his innovative style, using unconventional lineups and a run-and-gun offense while consistently producing playoff teams.

Though Nelson never won an NBA title as a coach, he’ll be inducted into the NBA Hall of Fame this summer in Springfield, Mass. Nelson said Saturday that he’s “pretty well” done coaching and currently immersed in business projects.

“What I thought would be a real simple off year, retirement has been one of the busiest years I’ve ever had,” Nelson said.

Nelson tried to earn his degree shortly after leaving Iowa. But basketball kept getting in the way. He took Spanish courses while he was with the Celtics to fulfill his requirement, but he mistakenly took just six credits rather than the required eight and put school off again. He earned four credits in Spanish while coaching at Golden State, but when Nelson called the university they said he still needed a student-teaching stint to graduate.

“I said ‘Well, it’s hard for me to do because my job is a 12-month job and I can’t get away to go to some high school and do that,” Nelson said.

Nelson put thoughts of graduating aside until he finally left coaching after the 2010-11 season, when he decided to do whatever needed to get his degree. Nelson initially forgot he’d taken more than enough Spanish to satisfy that requirement and dug up old transcripts to send them to Iowa.

The university officials also came to their senses and forgave Nelson’s student-teaching requirement because of the three-plus decades Nelson had spent coaching.

Nelson said he was inspired to get his degree by Shaquille O’Neal, who recently went back to LSU and got his degree. Nelson commended O’Neal on going for his master’s degree as well. But when Nelson was asked if he’s got any school left in him, his reply was quick.

“No, I’m done. I do have a Ph.D. already _ in basketball,” Nelson said.